Cold marches on -- at least until middle of month

Computer models suggest temperatures will remain well below normal through the middle of March, though there will be some brief thawing Friday and early next week.

At a time when afternoon readings normally rise to the low and middle 40s, most days may struggle to reach freezing. Monday's 19-degree high made it the coldest March 3 since 1884. The low was minus 2. March historically has seen less than 2 percent of the city’s below-zero temperatures.

The repeated polar outbreaks have preserved the snow cover across much of the Chicago area for an abnormally long period.

Observations at Midway Airport show there has been an inch or more of snow on the ground since Dec. 30. More snow may accumulate Tuesday night and Wednesday, adding to the five-inch snowpack that remained as of Monday evening.

The storm is gathering moisture over the Gulf and will be carried by the jet stream to the Chicago area overnight. Current indications are light snow could begin falling here late Tuesday night and occasional light snow may continue Wednesday, producing a possible accumulation of 1 to 3 inches.

That would be the 44th day of measurable snow this winter, something that hasn't happened in 129 years of snow records. The weekend snow brought this season's accumulation to 73.4 inches, more than 43 inches above normal.